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Manufacture of pultruded composite profiles in our company dates back in the year 1965. In that year we made the first pultrusion machine and started manufacturing profiles for professional military antennas. Later this program was expanded to many other fields.
So at present our line of Trivapul products includes a wide assortment of pultruded profiles as well as finished products: insulation profiles for electric power industry, construction profiles for antennas, anchors for stabilization of sliding earth, poles for electric fences, a series of draw rods for all types of electrical installations, corrosion resistant grating, thermal tunnels for agriculture, etc.
Most of our Trivapul profiles are made of glass fibres and unsaturated polyester resins. The fibres can be in the form of rovings, mats, fabrics, veils and combinations thereof. Polyester resins are selected according desired profile characteristics. For products that are exposed to heavy mechanical loading or aggressive chemicals, we use also epoxy and vinylester resins. If demands for strength and stiffness are very high we use carbon fibres.
Composites, therefore also Trivapul profiles, are anisotropic materials. Properties in different directions are not identical. Anisotropy is closely connected with orientation of the fibrous reinforcements. In the next table a few characteristics of three pultruded profiles with different composite construction are presented.
| property | unit | unidirectional E glass roving, polyester resin |
E glass roving, E glass mat, polyester resin |
unidirectional HT carbon fibres, epoxy resin |
| fibre content | vol % | 60 | 50 | 65 |
| density | Mg/m3 | 2.0 | 1.8 | 1.6 |
| specific heat | kJ/(kg*K) | 0.9 | 1.0 | 0.9 |
| thermal conductivity | W/(m*K) | L: 0.9 T: 0.4 | L: 0.4 T: 0.3 | L: 11 T: 0.6 |
| thermal expansion | 1/K*10E-6 | L: 7 T: 50 | L: 8 T: 30 | L: -0.2 T: 30 |
| tensile strength | GPa | L: 1.0 T: 0.04 | L: 0.4 T: 0.1 | L: 1.5 T: 0.06 |
| compressive strength | GPa | L: 0.7 T: 0.1 | L: 0.3 T: 0.15 | L: 1.2 T: 0.15 |
| tensile elastic modulus | GPa | L: 45 T: 7 | L: 25 T: 9 | L: 135 T: 9 |
| in plane shear strength | GPa | 0.04 | 0.04 | 0.06 |
| shear modulus | GPa | 4 | 4 | 5 |
| specific el. resistivity | Ohm*cm | L,T: >10E10 | L,T: >10E10 | L: <10E-3 |
| dielectric constant | 5 | 5 |
The technology of pultrusion enables the production of profiles very diverse in forms and dimensions. By applying different fibrous reinforcement types, different fibre arrangements, different resin systems and additives, characteristics of profiles can be varied in a broad range. Therefore, product quality can be suited to specific requirements in individual applications.
Our current pultrusion machines enable production of profiles with dimensions 500 mm x 180 mm. The existing die heating system supports products to around 120 mm. Profiles above 24 mm can be cut on machine to lengths up to 6 meters. Smaller profiles can be longer. Profiles up to 8 mm can be wound in coils.
| pultrusion machines permit products up to | 500 mm x 180 mm |
| existing die heating permits products up to | 120 mm x 120 mm |
| tolerances of cross-sectional dimensions | ASTM D 3917-80 |
| cross-sectional dimension |
cutting |
length |
tolerance |
| up to 120 mm | on machines | 1 m to 6 m | -0 mm +25 mm |
| up to 24 mm | on machines | > 6 m by agreement | -0 % +2 % |
| up to 8 mm | wound in coils | by agreement | -0 % +2 % |
| up to 120 mm | additional cutting | 50 mm to 6 m | ±0.5 mm to ±2 mm |
| up to 12 mm | precise cutting | 5 mm to 50 mm | ± 0.2 mm |
